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arXiv · 1609.02093

Dynamical complexity and controlled operator K-theory

Erik Guentner·Rufus Willett·Guoliang Yu
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Abstract

In this paper, we introduce a property of topological dynamical systems that we call finite dynamical complexity. For systems with this property, one can in principle compute the $K$-theory of the associated crossed product $C^*$-algebra by splitting it up into simpler pieces and using the methods of controlled $K$-theory. The main part of the paper illustrates this idea by giving a new proof of the Baum-Connes conjecture for actions with finite dynamical complexity. We have tried to keep the paper as self-contained as possible: we hope the main part will be accessible to someone with the equivalent of a first course in operator $K$-theory. In particular, we do not assume prior knowledge of controlled $K$-theory, and use a new and concrete model for the Baum-Connes conjecture with coefficients that requires no bivariant $K$-theory to set up.

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BibTeXRIS

Erik Guentner, Rufus Willett, Guoliang Yu. 2016-09-07. Dynamical complexity and controlled operator K-theory. https://arxiv.org/abs/1609.02093

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